﻿///winapi.cs is a mostly a code example which forces the windows form to occupy the
///entirety of the screen and to be displayed at the top.
///

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Runtime.InteropServices;
using System.Windows.Forms;
using System.Drawing;

namespace mainAppView
{
    /// <summary>
/// Selected Win API Function Calls
/// </summary>

public class WinApi
{
    [DllImport("user32.dll", EntryPoint = "GetSystemMetrics")]
    public static extern int GetSystemMetrics(int which);

    [DllImport("user32.dll")]
    public static extern void
        SetWindowPos(IntPtr hwnd, IntPtr hwndInsertAfter,
                     int X, int Y, int width, int height, uint flags);        

    private const int SM_CXSCREEN = 0;
    private const int SM_CYSCREEN = 1;
    private static IntPtr HWND_TOP = IntPtr.Zero;
    private const int SWP_SHOWWINDOW = 64; // 0×0040

    public static int ScreenX
    {
        get { return GetSystemMetrics(SM_CXSCREEN);}
    }

    public static int ScreenY
    {
        get { return GetSystemMetrics(SM_CYSCREEN);}
    }

    public static void SetWinFullScreen(IntPtr hwnd)
    {
        SetWindowPos(hwnd, HWND_TOP, 0, 0, ScreenX, ScreenY, SWP_SHOWWINDOW);
    }
}

/// <summary>
/// Class used to preserve / restore / maximize state of the form
/// </summary>
public class FormState
{
    private FormWindowState winState;
    private FormBorderStyle brdStyle;
    private bool topMost;
    private Rectangle bounds;

    private bool IsMaximized = false;

    public void Maximize(Form targetForm)
    {
        if (!IsMaximized)
        {
            IsMaximized = true;
            Save(targetForm);
            targetForm.WindowState = FormWindowState.Maximized;
            targetForm.FormBorderStyle = FormBorderStyle.None;
            targetForm.TopMost = true;
            WinApi.SetWinFullScreen(targetForm.Handle);
        }
    }

    public void Save(Form targetForm)
    {
        winState = targetForm.WindowState;
        brdStyle = targetForm.FormBorderStyle;
        topMost = targetForm.TopMost;
        bounds = targetForm.Bounds;
    }

    public void Restore(Form targetForm)
    {
        targetForm.WindowState = winState;
        targetForm.FormBorderStyle = brdStyle;
        targetForm.TopMost = topMost;
        targetForm.Bounds = bounds;
        IsMaximized = false;
    }
}
}
